Abstract. HPJava is an environment for scientific and parallel programming using Java. It is based on an extended version of the Java language. One feature that HPJava adds to Java is a multi-dimensional array, or multiarray, with properties similar to the arrays of Fortran. We are using Adlib as our high-level collective communication library. Adlib was originally developed using C++ by the Parallel Compiler Runtime Consortium (PCRC). Many functionalities of this high-level communication library is following its predecessor. However, many design issues are reconsidered and re-implemented according to Java environment. Detailed functionalities and implementation issues of this collective library will be described.